Hi Syabab,

Are you trying to create more checkbox items within the same workflow, having the same options? If that's the case, the quickest way is to duplicate the workflow, then modify them from the database.

You can try the following.
1. Save workflow A containing the field with 100 options as copy. Workflow B will be created.
2. Create new checkbox field in workflow A and save, do not create options.
3. Get the id of the new checkbox field in workflow A and the id of duplicated checkbox field in workflow B(attached).
4. In the #__social_field_options table, search for the options from workflow B and change their parent_id value to that of workflow A(id from step 3).